1. Field of Invention
The present invention relates to a display apparatus. More particularly, the present invention relates to a display apparatus comprising a lens with variating focus lengths and a display panel with pixels having non-periodically variating widths.
2. Description of Related Art
In the process for manufacturing a liquid crystal display (LCD), due to the causes from a panel circuit wiring layout, a mold frame and cutting tolerances, the frame border area located at four surrounding edges of a LCD panel cannot display any image, and thus an irremovable border area with non-light emitted is formed around the display panel, resulting in less viewable area on the display panel. In order to reduce the border area with non-light emitted for magnifying the viewable area on the display panel, a conventional skill is directed to mounting a magnifying lens or circular Fresnel lens above a LCD panel for directly performing 2-dimensional area magnification to shield the aforementioned non-light emitting border area by generating a virtual image.
However, the conventional skill using the magnifying lens may cause sever spherical aberration and chromatic aberration, and the lens itself is quite heavy and thick, and thus is disadvantageous to the application of portable display emphasizing the features of lightness and thinness. As to the conventional skill using the circular Fresnel lens, although it may be able to reduce the thickness and weight of the lens, yet the periodical structure of the Fresnel lens may interfere with the pixels area on the LCD panel to cause interference stripes, such as Moire patterns, etc. Particularly, when being viewed with a large slant view angle, the image shown on the LCD panel is further affected by an overlarge facet angle or slope angle of a micro-prism structure on the circular Fresnel lens, and darker and lighter stripes or ghosting phenomena are generated thereby, thus resulting in visual defects.